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Shamblott MJ, Cheng CM, Bolt D, Chen TT. Appearance of insulin-like growth factor mRNA in the liver and pyloric ceca of a teleost in response to exogenous growth hormone. Proc Natl Acad Sci U S A 1995; 92:6943-6. [PMID: 7624349 PMCID: PMC41447 DOI: 10.1073/pnas.92.15.6943] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Augmentation of vertebrate growth by growth hormone (GH) is primarily due to its regulation of insulin-like growth factor I (IGF I) and IGF II levels. To characterize the effect of GH on the levels of IGF I and IGF II mRNA in a teleost, 10 micrograms of bovine GH (bGH) per g of body weight was administered to juvenile rainbow trout (Oncorhynchus mykiss) through i.p. injection. The levels of IGF I and IGF II mRNA were determined simultaneously, by using RNase protection assays, in the liver, pyloric ceca, kidney, and gill at 0, 1, 3, 6, 12, 24, 48, and 72 hr after injection. In the liver, IGF I mRNA levels were significantly elevated at 6 and 12 hr (approximately 2- to 3-fold, P < or = 0.01), while IGF II mRNA levels were significantly elevated at 3 and 6 hr (approximately 3-fold, P < or = 0.01). In the pyloric ceca, IGF II mRNA levels were significantly elevated at 12, 24, and 48 hr (approximately 3-fold, P < or = 0.01), while IGF I mRNA was below the limits of assay accuracy. GH-dependent IGF mRNA appearance was not detected in the gill and kidney. Serum bGH levels, determined by using a radioimmunoassay, were significantly elevated at 3 and 6 hr (P < 0.005). In primary hepatocyte culture, IGF I and IGF II mRNA levels increased in a bGH dose-dependent fashion, with ED50 values of approximately 45 and approximately 6 ng of bGH per ml, respectively. The GH-dependent appearance of IGF II mRNA in the liver and pyloric ceca suggests important roles for this peptide hormone exclusive of IGF I.
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Marsh AG, Chen TT. A divergent cDNA homologue of the c-myc proto-oncogene in the eastern oyster Crassostrea virginica: implications for Myc evolution. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1995; 4:185-192. [PMID: 7773336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The polymerase chain reaction was used to identify myc-like cDNA fragments from several marine invertebrate phyla. A PCR clone produced from the eastern oyster Crassostrea virginica was subsequently used to screen a larval cDNA library, and a 1.9-kb cDNA clone was isolated and sequenced. The putative amino acid sequence encoded by this clone evidences a leucine zipper at its predicted carboxyl-terminus and has an overall structural similarity to vertebrate c-myc proto-oncogenes with several regions of high amino acid similarity. However, this oyster cDNA clone lacks the necessary amino acid conservation in the critical functional domains of Myc and thus is unlikely to function intracellularly in the oyster as a true homologue of vertebrate c-myc. We propose that the oyster cDNA clone described here represents a gene that has been derived from the same ancestral gene that eventually gave rise to vertebrate c-myc. Despite the apparent critical importance of the c-myc proto-oncogene in regulating cellular activities, these data suggest that the c-myc gene: (1) is unique to deuterostome phyla, and (2) assumed its critical role in regulating cell cycle activities at the divergence of the deuterostome ancestors from other protostomes during the Cambrian explosion. In support of these conclusions we present a functional model for the evolution of the Myc gene.
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Bols NC, Yang BY, Lee LE, Chen TT. Development of a rainbow trout pituitary cell line that expresses growth hormone, prolactin, and somatolactin. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1995; 4:154-163. [PMID: 7773333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A cell line, RTP-2, has been developed from a normal-appearing pituitary of an adult rainbow trout. The cells grow in L-15 basal medium, supplemented with 2.5% to 10% fetal bovine serum, and have been passaged approximately 50 times over a 2-year period. At low density the cells have a stellate shape, whereas at confluency islands of polygonal cells appear among a tangle of bipolar cells. At the ultrastructural level, most cells contain numerous lysosomes, autophagic vacuoles, and intermediate filaments, but no obvious secretory granules. Reverse transcription-polymerase chain reaction (RT-PCR) with oligonucleotides specific for growth hormone (GH), prolactin (PRL), and somatolactin (SL) as amplification primers and Southern blot hybridization of the PCR products with probes specific for GH, PRL, and SL demonstrate that this cell line expresses GH, PRL, and SL. Digestion of the GH product of RT-PCR with restriction endonuclease SalI or KpnI confirms that both rainbow trout growth hormone genes are expressed in this cell line.
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Chen TT, Levy R. Induction of autoantibody responses to GM-CSF by hyperimmunization with an Id-GM-CSF fusion protein. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1995; 154:3105-17. [PMID: 7897201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Fusion proteins consisting of an Ig containing xenogenic constant regions and granulocyte-macrophage colony stimulating factor (Id-GM-CSF) are potent immunogens capable of inducing anti-idiotypic Abs after two immunizations, without the usual need for adjuvants or carrier proteins. In this study, we investigated the effects of hyperimmunization with Id-GM-CSF and found that it induces anti-GM-CSF Abs that could bind to GM-CSF and neutralize its bioactivity in vitro. However, no detrimental effects of the anti-GM-CSF activity were apparent on the general health of the animals or on their base line white blood cell counts. Mice with the anti-GM-CSF activity reconstituted their peripheral white blood cells with identical kinetics as control mice after high dose cyclophosphamide treatment, sublethal irradiation, or lethal irradiation followed by syngeneic bone marrow transplantation. Primary and secondary Ab responses to a variety of protein Ags, including an unrelated Ig Id, were not affected. However, the anti-Id response induced by an unrelated GM-CSF fusion protein that is dependent upon the GM-CSF bioactivity was impaired. To avoid any potential problems associated with inducing anti-GM-CSF Abs, we show that priming with the Id-GM-CSF protein and boosting with the Id protein alone were sufficient to induce comparable anti-Id titers without inducing anti-GM-CSF Abs. We conclude that although hyperimmunization of mice with the GM-CSF fusion protein induced neutralizing anti-GM-CSF Abs, this was of little consequence to the animals. Nevertheless, we have devised a strategy to overcome this potential limitation on the use of GM-CSF fusion proteins for immunization.
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105
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Chen TT, Levy R. Induction of autoantibody responses to GM-CSF by hyperimmunization with an Id-GM-CSF fusion protein. THE JOURNAL OF IMMUNOLOGY 1995. [DOI: 10.4049/jimmunol.154.7.3105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Fusion proteins consisting of an Ig containing xenogenic constant regions and granulocyte-macrophage colony stimulating factor (Id-GM-CSF) are potent immunogens capable of inducing anti-idiotypic Abs after two immunizations, without the usual need for adjuvants or carrier proteins. In this study, we investigated the effects of hyperimmunization with Id-GM-CSF and found that it induces anti-GM-CSF Abs that could bind to GM-CSF and neutralize its bioactivity in vitro. However, no detrimental effects of the anti-GM-CSF activity were apparent on the general health of the animals or on their base line white blood cell counts. Mice with the anti-GM-CSF activity reconstituted their peripheral white blood cells with identical kinetics as control mice after high dose cyclophosphamide treatment, sublethal irradiation, or lethal irradiation followed by syngeneic bone marrow transplantation. Primary and secondary Ab responses to a variety of protein Ags, including an unrelated Ig Id, were not affected. However, the anti-Id response induced by an unrelated GM-CSF fusion protein that is dependent upon the GM-CSF bioactivity was impaired. To avoid any potential problems associated with inducing anti-GM-CSF Abs, we show that priming with the Id-GM-CSF protein and boosting with the Id protein alone were sufficient to induce comparable anti-Id titers without inducing anti-GM-CSF Abs. We conclude that although hyperimmunization of mice with the GM-CSF fusion protein induced neutralizing anti-GM-CSF Abs, this was of little consequence to the animals. Nevertheless, we have devised a strategy to overcome this potential limitation on the use of GM-CSF fusion proteins for immunization.
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Gothilf Y, Elizur A, Chow M, Chen TT, Zohar Y. Molecular cloning and characterization of a novel gonadotropin-releasing hormone from the gilthead seabream (Sparus aurata). MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1995; 4:27-35. [PMID: 7749463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A novel form of gonadotropin-releasing hormone (GnRH) had been recently isolated and characterized from the gilthead seabream (Sparus aurata). This novel form, designated sbGnRH, was suggested to be the endogenous stimulator of gonadotropin release. This paper reports on the isolation and characterization of a 360-bp cDNA encoding the complete sbGnRH precursor. This precursor is composed of a 25 amino acid leader sequence, the biologically active sbGnRH, the cleavage site (Gly-Lys-Arg), and a 57 amino acid associated peptide (GAP). Comparison of the nucleotide and amino acid sequence of the sbGnRH precursor with precursors of other GnRH forms places the sbGnRH precursor evolutionarily closer to the mammalian GnRH and chicken GnRH-I, which have also been shown to be the relevant forms for gonadotropin release in mammals and birds, respectively. The characterization of the sbGnRH precursor cDNA lays the foundation for future studies aimed toward understanding the neuroendocrine control of reproduction in seabream and other fish species.
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Cheng CM, Lin CM, Shamblott M, Gonzalez-Villasenor LI, Powers DA, Woods C, Chen TT. Production of a biologically active recombinant teleostean growth hormone in E. coli cells. Mol Cell Endocrinol 1995; 108:75-85. [PMID: 7758842 DOI: 10.1016/0303-7207(94)03458-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have isolated and characterized several recombinant lambda phage clones carrying growth hormone (GH) cDNA of striped bass (Morone saxatilis). Nucleotide sequence and the predicted amino acid sequence of sbGH was determined from a recombinant clone carrying the longest cDNA insert. The sbGH cDNA encodes a pre-hormone of 204 amino acid residues. Comparison of the predicted amino acid sequence of sbGH with those of other vertebrates revealed different degrees of sequence identity: approximately 98% with European sea bass; 90% with bluefin tuna; bonito and red seabream; 71% with winter flounder; 64% with salmonids; 55% with carp; and 38% with human. Expression of the mature sbGH cDNA (without the signal peptide sequence) in E. coli cells under regulation of the lambda phage PL promoter produced a polypeptide of 20 kDa. Following renaturation, this recombinant hormone was shown to be biologically active in a radioreceptor competition binding assay and in the induction of hepatic insulin-like growth factor I (IGF-I) mRNA synthesis in vivo.
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Chen TT, Tao MH, Levy R. Idiotype-cytokine fusion proteins as cancer vaccines. Relative efficacy of IL-2, IL-4, and granulocyte-macrophage colony-stimulating factor. THE JOURNAL OF IMMUNOLOGY 1994. [DOI: 10.4049/jimmunol.153.10.4775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Idiotypic determinants, antigenic sites expressed on the variable region of Ig molecules of malignant B cells, represent tumor-specific Ags but are weak immunogens. We have previously shown that the immunogenicity can be dramatically increased by fusing tumor Id to granulocyte macrophage (GM)-CSF. Here, we demonstrate that fusion proteins with IL-2 or IL-4 can also be highly immunogenic. Co-immunization of these fusion proteins with another Id demonstrated the importance of physical linkage between the cytokine and relevant Ag for this enhancement. All three fusion proteins are capable of eliciting significant levels of specific Abs against the Id without the use of carrier proteins or adjuvants, although the GM-CSF fusion protein appeared to be unique in its ability to induce higher titers of anti-Id Abs in the primary response. Furthermore, the Id-IL-2 fusion protein induced high titers of IgG2a and IgG3 anti-Id Abs, whereas the Id-IL-4 and Id-GM-CSF fusion proteins did not. Despite the differences, tumor protection was comparable in all mice having significant titers of anti-Id Abs, regardless of the fusion protein used. We concluded that Id-cytokine fusion proteins are potent immunogens that can elicit significant antitumor immunity. The general approach of fusing a cytokine to a potential Ag may be applicable to the design of vaccines for immunotherapy of other types of tumors as well as for other pathogens and disease states.
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Chen TT, Tao MH, Levy R. Idiotype-cytokine fusion proteins as cancer vaccines. Relative efficacy of IL-2, IL-4, and granulocyte-macrophage colony-stimulating factor. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1994; 153:4775-87. [PMID: 7525715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Idiotypic determinants, antigenic sites expressed on the variable region of Ig molecules of malignant B cells, represent tumor-specific Ags but are weak immunogens. We have previously shown that the immunogenicity can be dramatically increased by fusing tumor Id to granulocyte macrophage (GM)-CSF. Here, we demonstrate that fusion proteins with IL-2 or IL-4 can also be highly immunogenic. Co-immunization of these fusion proteins with another Id demonstrated the importance of physical linkage between the cytokine and relevant Ag for this enhancement. All three fusion proteins are capable of eliciting significant levels of specific Abs against the Id without the use of carrier proteins or adjuvants, although the GM-CSF fusion protein appeared to be unique in its ability to induce higher titers of anti-Id Abs in the primary response. Furthermore, the Id-IL-2 fusion protein induced high titers of IgG2a and IgG3 anti-Id Abs, whereas the Id-IL-4 and Id-GM-CSF fusion proteins did not. Despite the differences, tumor protection was comparable in all mice having significant titers of anti-Id Abs, regardless of the fusion protein used. We concluded that Id-cytokine fusion proteins are potent immunogens that can elicit significant antitumor immunity. The general approach of fusing a cytokine to a potential Ag may be applicable to the design of vaccines for immunotherapy of other types of tumors as well as for other pathogens and disease states.
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110
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Wu RL, Chen TT, Sun TT. Functional importance of an Sp1- and an NFkB-related nuclear protein in a keratinocyte-specific promoter of rabbit K3 keratin gene. J Biol Chem 1994; 269:28450-9. [PMID: 7525574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We have shown previously that a 300-base pair (bp) 5' upstream sequence of rabbit keratin K3 gene (RK3) can function as a keratinocyte-specific promoter in transient transfection assays. Electrophoretic mobility shift assays using various overlapping and mutated oligonucleotides established that corneal keratinocyte nuclear proteins bound in vitro to two sites (B and E). Immunosupershift and UV cross-linking established that the keratinocyte nuclear binding protein of site B (5'-GGGGCTTTCC-3', -262 to -253 bp) was NFkB consisting of the p65 and p50 subunits. The E site contained an unusual GC-rich motif (5'-CCGCCCCCTG-3', -203 to -194 bp) whose sequence deviated from the Sp1 consensus in 4 out of 10 positions; this site bound an Sp 1-related keratinocyte nuclear protein. Mutagenesis of the NFkB, GC motif, and both sites abolished 20, 50, and 75%, respectively, of the promoter activity in transfected keratinocytes. The NFkB-like keratinocyte nuclear protein was barely detectable in kidney epithelial cells, HeLa, and fibroblasts. The Sp1-related nuclear protein was abundant in keratinocytes and simple epithelial cells, but was much less abundant in fibroblasts. These results indicate that NFkB is present in significant quantities in keratinocyte nuclei and that the tissue restriction of the NFkB- and Sp1-related proteins, in combination with other factors, may contribute to the keratinocyte specificity of RK3 promoter.
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Wu RL, Chen TT, Sun TT. Functional importance of an Sp1- and an NFkB-related nuclear protein in a keratinocyte-specific promoter of rabbit K3 keratin gene. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)46948-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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112
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Keenan JA, Chen TT, Chadwell NL, Torry DS, Caudle MR. Interferon-gamma (IFN-gamma) and interleukin-6 (IL-6) in peritoneal fluid and macrophage-conditioned media of women with endometriosis. Am J Reprod Immunol 1994; 32:180-3. [PMID: 7880401 DOI: 10.1111/j.1600-0897.1994.tb01111.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PROBLEM The presence of the various cytokines in human peritoneal fluid has been incompletely evaluated. Changes in cytokine levels may be related to activation of peritoneal macrophages, development of endometriosis, and infertility. This study assesses peritoneal fluid levels of interferon gamma (IFN-gamma) and interleukin-6 (IL-6), and peritoneal macrophage production of IL-6, in women with and without endometriosis. METHOD Peritoneal fluid was obtained from 62 women at the time of diagnostic or operative laparoscopic surgery for benign gynecologic disease. Peritoneal macrophages were isolated, cultured for 24 h, and the culture media collected. IFN-gamma and IL-6 levels in peritoneal fluid samples and macrophage conditioned media were determined by commercial ELISA. RESULTS IL-6 was significantly higher in the macrophage conditioned media of women with endometriosis as compared with controls. IL-6 levels were fourfold higher in early stage endometriosis (P < 0.05) and eightfold higher in advanced endometriosis. There were no significant differences between groups in the peritoneal fluid levels of IL-6 or IFN-gamma. CONCLUSIONS Peritoneal macrophage IL-6 secretion is increased in women with endometriosis, and appears to correlate with disease stage. IFN-gamma does not appear to be responsible for the activation of macrophages in women with endometriosis.
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113
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Korn EL, Midthune D, Chen TT, Rubinstein LV, Christian MC, Simon RM. A comparison of two phase I trial designs. Stat Med 1994; 13:1799-806. [PMID: 7997713 DOI: 10.1002/sim.4780131802] [Citation(s) in RCA: 238] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Phase I cancer chemotherapy trials are designed to determine rapidly the maximum tolerated dose of a new agent for further study. A recently proposed Bayesian method, the continual reassessment method, has been suggested to offer an improvement over the standard design of such trials. We find the previous comparisons did not completely address the relative performance of the designs as they would be used in practice. Our results indicate that with the continual reassessment method, more patients will be treated at very high doses and the trials will take longer to complete. We offer some suggested improvements to both the standard design and the Bayesian method.
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Chen TT, Massey PJ, Caudle MR. The inhibitory action of taxol on granulosa cell steroidogenesis is reversible. Endocrinology 1994; 134:2178-83. [PMID: 7908872 DOI: 10.1210/endo.134.5.7908872] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Taxol is a novel anticancer agent extracted from the bark of Pacific yew trees. The drug has been approved by the FDA for the treatment of advanced ovarian cancer and is in clinical trials for other malignancies, including breast cancer. The goals of this study were to determine whether taxol adversely and irreversibly affects ovarian granulosa cell steroidogenesis. Cultured porcine granulosa cells were treated with taxol (0.12-12 microM) or vehicle (0.01-1% ethanol) in the absence or presence of 10(-9) M hCG in a time- and dose-response study. Morphological changes were recorded every 2 h, and media were collected for the measurement of progesterone (P4) and 17 beta-estradiol. Taxol suppressed both basal P4 and 17 beta-estradiol production and hCG-stimulated P4 production in a time- and dose-dependent manner and drastically changed cell shape by causing disorganization of microtubule bundles and other subcellular organelles. hCG partially reversed the steroid inhibition induced by taxol. These changes are not attributed to ethanol used as the vehicle, because ethanol at higher concentrations than that present in taxol did not suppress P4 production. When taxol was removed from the culture, P4 production returned to control levels. The results of this study show that taxol causes a significant, but reversible, inhibition of granulosa cell steroidogenesis. This inhibitory effect can be partially overcome by co-treatment with hCG.
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Berndtson AK, Chen TT. Two unique CYP1 genes are expressed in response to 3-methylcholanthrene treatment in rainbow trout. Arch Biochem Biophys 1994; 310:187-95. [PMID: 8161204 DOI: 10.1006/abbi.1994.1156] [Citation(s) in RCA: 114] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In animals, exposure to polyaromatic hydrocarbons (PAHs) such as 3-methylcholanthrene (3-MC) is known to induce the expression of two unique cytochrome P450 genes, CYP1A1 and CYP1A2. These genes are thought to have originated by a gene duplication event and diverged no more than 250 million years ago (D. W. Nerbert and F. J. Gonzalez, 1987, Annu. Rev. Biochem. 56, 945-993). Lower vertebrates, such as fish, diverged from land animals before this time and are thought to express only a single CYP1 gene. In this paper, we present evidence to refute this hypothesis and report the isolation and complete genomic nucleotide sequence of two distinct CYP1 genes in rainbow trout. Genomic clones encoding the entire CYP1A1 and CYP1A2 genes were characterized. DNA sequence analysis revealed that both genes contained seven exons and six introns. Exons 1-7 of CYP1A1 and CYP1A2 were highly similar in length and nucleotide sequence. In contrast, the 5'-flanking region and introns 1, 2, 5, and 6 of both genes were significantly less conserved. Two xenobiotic regulatory elements (XREs) were identified in the 5'-flanking region of CYP1A1 but not in that of CYP1A2. The 5'-most start site of transcription was determined to begin at a cytosine residue 27 bases downstream of the putative TATA box of both genes. Northern blot analysis demonstrated that exposure to 3-MC resulted in an increase in CYP1 mRNA levels in the liver. RNase protection assays conducted with riboprobes specific for either CYP1A1 or CYP1A2 confirmed that the transcripts of both genes were expressed in rainbow trout liver in response to 3-MC treatment.
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Chen TT, Simon RM. Extension of one-sided test to multiple treatment trials. CONTROLLED CLINICAL TRIALS 1994; 15:124-34. [PMID: 8205803 DOI: 10.1016/0197-2456(94)90016-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In a two-treatment clinical trial, a one-sided test is sometimes used in reaching a decision. Usually we are interested in doing a one-sided test because of the existence of an unequal preference between the two treatments. When a standard control is just as good or better than the new experimental treatment (which has more toxicity or cost), we will stay with the standard control. In this paper, we extend the concept of a one-sided test to the multiple treatment trial where three or more treatments are involved. We assume that there is an order of strictly decreasing preference among the treatments. We propose two multiple-step decision procedures that are similar to the bubble sorting algorithm and will guarantee a high probability of finally selecting the correct treatment. We also provide methods to calculate the sample size required to detect a specific difference. The derivation is based on normal data, and the extension to binomial or exponential data with random censoring is through large sample approximation.
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Abstract
In some multiple treatment arm clinical trials there is an order of preference for the treatments based on secondary considerations like toxicity or cost. In this paper, we consider the case where two or more treatments could have equal prior preference. This formulation includes the problem of comparing several equally preferred experimental treatments to one control, or the comparison of a combination with its components. Our decision procedures will guarantee a high selection probability for the correct treatment(s) when that selection is appropriate. We establish sample size requirements for our decision procedures which can be applied to clinical trials with normal, binomial, or right censored exponential endpoints.
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Shamblott MJ, Chen TT. Age-related and tissue-specific levels of five forms of insulin-like growth factor mRNA in a teleost. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1993; 2:351-61. [PMID: 8193670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A reverse transcriptase/PCR assay was employed to amplify an internal portion of insulin-like growth factor I (IGF I) and IGF II cDNA from the RNA of juvenile rainbow trout (Oncorhynchus mykiss) in an effort to detect analogues to the multiple size forms of IGF mRNA known to exist in mammals. After cloning and sequencing the PCR products, 4 variant size forms of trout IGF I mRNA and 1 form of IGF II mRNA were evident. The full cDNA nucleotide sequence of 1 form of IGF I mRNA and IGF II mRNA have been previously reported; the full cDNA nucleotide sequence of a second form of IGF I mRNA and PCR-derived nucleotide sequences of the 2 additional IGF I mRNA forms are reported herein. We define the 4 forms of IGF I mRNA (IGF IEa-1, Ea-2, Ea-3, and Ea-4) as having E-domain peptide lengths of 35, 47, 62, and 74 predicted amino acid residues, respectively. RNAse protection assays were used to quantify the mRNA levels of each of the 5 IGFs in 8 tissues of both juvenile and adult trout, as well as in testes and ovaries of adult trout. The IGF mRNA levels, normalized with 18S rRNA levels, suggest (1) at least 1 form of IGF I and IGF II mRNA are present at both developmental stages in all tissues examined; (2) all 5 IGF mRNA forms are present at their highest levels in the liver (p < 0.05); and (3) adults have significantly higher IGF mRNA levels than juveniles in the liver (p = 0.0047).
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Chen TT, Simon R. A multiple-step selection procedure with sequential protection of preferred treatments. Biometrics 1993; 49:753-61. [PMID: 8241371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Dunnett (1955, Journal of the American Statistical Association 50, 1096-1121) proposed a one-step many-one test to compare several experimental treatment means with a control. However, after the control treatment is rejected, one would want to make comparisons among the experimental treatments. We assume that there is an order of decreasing preference among the experimental treatments based on other considerations. We propose in this paper a multiple-step selection procedure, an extension of Dunnett's one-step many-one test that will give protection to the preferred treatments and guarantee a high selection probability of the correct treatment when that selection is appropriate. We also provide methods to calculate the sample size required to carry out this test for normal, binomial, and exponential data with random censoring.
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Tang Y, Lin CM, Chen TT, Kawauchi H, Dunham RA, Powers DA. Structure of the channel catfish (Ictalurus punctatus) growth hormone gene and its evolutionary implications. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1993; 2:198-206. [PMID: 8293072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A DNA fragment of 1.6 kilo base pairs (kb), encoding part of the channel catfish (Ictalurus punctatus) growth hormone (GH) gene, was generated by the polymerase chain reaction (PCR) using 2 degenerate synthetic oligonucleotides (30 and 33 mer) derived from the N- and C-terminal amino acid sequences of the catfish GH polypeptide as amplification primers and with catfish genomic DNA as a template. This DNA fragment was used as a probe for the isolation of a catfish GH gene from a genomic library constructed in a lambda phage cloning vector, lambda Dash II. Three positive clones were isolated, and their complete nucleotide sequences were determined. Nucleotide sequences from clones 1 and 3 were identical, whereas clone 2 had 2 base substitutions. The gene spans approximately 3 kb and is comprised of 5 exons and 4 introns. The initiation codon, the termination codon, and the canonical polyadenylation sequence were identified. The amino acid sequence deduced from the predicted coding region of the gene is in agreement with that of the native GH polypeptide sequence. A sequence (TATAAAA) matching the TATA box consensus sequence was located at nucleotide positions -30 to -23. Furthermore, 2 sequences corresponding to the mammalian Pit-1/GHF-1 binding sites (consensus sequence TT[AA]TATNCAT) were identified in the 5' flanking region starting at positions -113 and -134. Another sequence (GTACCAGTGA) conserved among the GH genes of the channel catfish and other known animal species was also identified at position -220. The biological functions of this sequence remain to be determined.(ABSTRACT TRUNCATED AT 250 WORDS)
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Bukovský A, Chen TT, Wimalasena J, Caudle MR. Cellular localization of luteinizing hormone receptor immunoreactivity in the ovaries of immature, gonadotropin-primed and normal cycling rats. Biol Reprod 1993; 48:1367-82. [PMID: 8318590 DOI: 10.1095/biolreprod48.6.1367] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
In this study we used two monoclonal antibodies against purified LH receptor (LHR) to localize and quantify LHR in ovarian compartments during follicular development, using gonads from immature, gonadotropin-primed, and normal cycling rats. In early preantral follicles, LHR immunoreactivity (LHRI) was identified in vascular endothelium and subsequently appeared in vascular pericytes. In healthy small antral (200-550-microns) follicles, LHRI continued to be present in thecal pericytes, but not in cells of the theca interna. However, in small antral follicles undergoing atresia, a dramatic decrease in thecal vessel LHRI with a concomitant increase in LHRI in hypertrophied theca was observed. In healthy antral follicles, LHRI of thecal cells was not observed until the cells reached medium (550-microns) size. High LHRI was occasionally observed in macrophage-like cells adjacent to the oocyte of large preantral follicles and among granulosa layers of medium-sized antral follicles. In the membrana granulosa, LHRI first appeared in cumulus cells of medium-sized antral follicles and subsequently spread to the entire granulosa cell population of large (750 microns) antral follicles. Treatment of immature rats with eCG markedly enhanced LHRI in theca and granulosa cells of all antral follicles, while eCG/hCG-treated (pseudopregnant) rats showed lack of LHRI in follicles and interstitial glands, but not in corpora lutea (CL). Within degenerating CL in the cycling ovary, compared to fresh and mature CL, a significant decrease occurred in intracellular LHRI. Our observations indicate that 1) vascular pericytes may play a role in follicular development; 2) LHR expression in granulosa may require an interaction of macrophages, oocytes, and cumulus cells; and 3) thecal hypertrophy accompanied by enhanced LHR expression occurs on follicles undergoing atresia.
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Tsai HJ, Lin KL, Chen TT. Molecular cloning and expression of yellowfin porgy (Acanthopagrus latus houttuyn) growth hormone cDNA. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1993; 104:803-10. [PMID: 8472546 DOI: 10.1016/0305-0491(93)90216-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. The growth hormone cDNA of yellowfin porgy (ypGH cDNA) consisted of 915 base pairs. 2. The deduced amino acid (aa) sequence showed that the pre-GH comprised 204 residues, of which the first 17 residues formed a signal peptide. 3. Comparison of aa sequence of ypGH to seabream, tuna, rainbow trout and chum salmon showed that ypGH shared 95.1, 94.1, 65.3 and 62.4% homology with these species, respectively. 4. By expressing the ypGH cDNA in E. coli, a polypeptide around 23 kilodaltons (kDa) was found which was immunoreactive to GH antibody.
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Chen TT, Kight K, Lin CM, Powers DA, Hayat M, Chatakondi N, Ramboux AC, Duncan PL, Dunham RA. Expression and inheritance of RSVLTR-rtGH1 complementary DNA in the transgenic common carp, Cyprinus carpio. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1993; 2:88-95. [PMID: 8364692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Transgenic common carp, Cyprinus carpio, possessing the long terminal repeat (LTR) sequence of avian Rous sarcoma virus (RSV) fused to the rainbow trout (rt) growth hormone (GH1) complementary DNA (cDNA) were produced by microinjection. Initial studies showed that the transgenic common carp transmitted the foreign DNA to a significant fraction of their progeny in three of four crosses of transgenic males with control females. These progeny grew 20 to 40% faster than their nontransgenic full siblings. In this study, additional experiments were conducted to evaluate inheritance and expression of the foreign GH gene in transgenic common carp, and the growth performance of these transgenic fish. Four P1 (parental generation produced by microinjection) x nontransgenic controls, four P1 x P1, and one P1 x F1 matings of transgenic carp containing RSVLTR-rtGH1 cDNA were made. The percentages of transgenic progeny resulting from these matings were: 0, 32, 42, 100 (4 progeny only), 21, 21, 31, 30, and 23%, respectively. All crosses except 1 siblot (control x P1) exhibited progeny ratios below the expected 50 or 75% transgenic. These results indicate that most of these transgenic P1 had the foreign gene in their germ line but were mosaics, and at least one transgenic individual did not have the RSVLTR-rtGH1 cDNA in the gonadal tissue. Both P1 and F1 transgenic fish produce trout growth hormone mRNA and polypeptide as determined by reverse transcription polymerase chain reaction amplification, RNA dot-blot hybridization, and radio-immunobinding assay. Growth response by families of F1 transgenic fish to the addition of rtGH1 cDNA varied widely.(ABSTRACT TRUNCATED AT 250 WORDS)
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Shamblott MJ, Chen TT. Identification of a second insulin-like growth factor in a fish species. Proc Natl Acad Sci U S A 1992; 89:8913-7. [PMID: 1409585 PMCID: PMC50034 DOI: 10.1073/pnas.89.19.8913] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
An internal portion of insulin-like growth factor (IGF) amplified from the total cDNA of rainbow trout (Oncorhynchus mykiss) liver by a PCR was used to screen a rainbow trout liver cDNA library, and recombinant clones encoding two distinct IGFs were isolated. On the basis of a 98.7% nucleotide and 98.3% predicted amino acid identity to coho salmon IGF-I, one cDNA sequence was identified as rainbow trout preproinsulin-like growth factor I (rtIGF-I). The second cDNA sequence shared 46.1% and 43.3% identity with rtIGF-I at the nucleotide and predicted amino acid levels, respectively, and was identified as rainbow trout preproinsulin-like growth factor II (rtIGF-II). Predicted amino acid sequence comparisons of rtIGFs with those of human IGFs indicate that rtIGF-I is more similar to human IGF-I than to human IGF-II, and that rtIGF-II is more similar to human IGF-II than to human IGF-I. Southern blot analysis of rainbow trout genomic DNA probed with rtIGF-I and -II cDNA suggests that these two forms of IGF originate from separate genes. The presence of a teleost IGF-II suggests that the divergence of IGFs occurred early in vertebrate evolution.
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Bahler DW, Zelenetz AD, Chen TT, Levy R. Antigen selection in human lymphomagenesis. Cancer Res 1992; 52:5547s-5551s. [PMID: 1394171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Although surface immunoglobulin plays a central role in the differentiation and growth of normal B-cells, its role in the growth of human B-cell malignancies is largely a matter of conjecture. Human follicular lymphomas are attractive systems to study in part because they are clones of cells sharing many similarities with germinal center B-cells which are critically dependent on antigen selection for survival. Nucleotide sequence information was determined for the immunoglobulin heavy chain variable genes expressed by two cases of follicular lymphoma. In addition, the germ line variable gene counterparts were also cloned and sequenced from biopsy material obtained from both of these patients. Numerous mutations from germ line were present in the variable genes from both of these cases, many of which accumulated during expansion and growth of these lymphomas. Moreover, the mutations that accumulated during tumor expansion were distributed in a manner that almost certainly was dependent on positive selection presumably mediated by contact with an antigen. These data indicate that antigen selection is probably important for the growth and clonal evolution of follicular lymphomas.
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Zelenetz AD, Chen TT, Levy R. Clonal expansion in follicular lymphoma occurs subsequent to antigenic selection. J Exp Med 1992; 176:1137-48. [PMID: 1402658 PMCID: PMC2119381 DOI: 10.1084/jem.176.4.1137] [Citation(s) in RCA: 124] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The genesis of human follicular lymphoma (FL) is a multistep process. The initial event is thought to be the chromosomal translocation t(14;18)(q32;q21) juxtaposing the bcl-2 proto-oncogene with the immunoglobulin (Ig) H chain locus joining segment (JH) as an error of D-J or V-D joining in the pre-B cell. However, FL is recognized clinically as a tumor of surface Ig (sIg)-positive B cells with morphologic and phenotypic similarities to the centrocyte of the secondary immune response. Thus, additional steps must be involved in the clonal expansion of the FL tumor cell beyond the activation of bcl-2 as a consequence of the t(14;18) translocation. Like the normal centrocyte, somatic mutations accumulate in the variable (V) genes of FL tumor B cells. To determine if clonal expansion of FL occurs before or after the development of the malignant follicle, we sought to examine the evolution of the FL V gene from its unmutated germline (GL) counterpart. To obtain the GL gene we first cloned the productively rearranged V gene of patient MT FL and obtained the clone rMTF. A hybridization probe derived from the 2.1-kb region upstream of the V gene in clone rMTF identified a single band in Southern blot hybridization of GL DNA. This probe was used to screen a size-selected library, and candidate GL V genes were isolated. Two identical clones, MTGL1 and 2, proved to have upstream regions (USRs) that were colinear with the USR of the rMTF. Thus, the MTGL clones represent the unmutated GL V genes, which were productively rearranged in the MT FL. Comparison of the GL V gene sequence to a consensus of MT FL V gene sequences revealed 42 mutations, demonstrating that malignant clonal expansion occurred subsequent to the activation of somatic mutation, presumably in the malignant follicle. Furthermore, the individual FL V gene sequences segregated into two distinct patterns of mutation. The major population represented 71% of the clones, and the minor population 29%. To investigate possible mechanisms for the parallel selection of distinct tumor cell populations, we analyzed the pattern of silent and replacement mutations within the V gene sequences. We found that in the framework regions (FRs) of both populations there were significantly fewer replacement changes than expected, suggesting that negative selective pressure was maintaining the structural integrity of the sIg. In contrast, the complementarity determining regions (CDRs), which make up the antigen binding domain of Ig, had an excess of replacement changes, suggesting positive selection for altered ligand binding.
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MESH Headings
- Base Sequence
- Blotting, Southern
- Chromosomes, Human, Pair 14
- Chromosomes, Human, Pair 18
- Cloning, Molecular
- DNA, Neoplasm/genetics
- DNA, Neoplasm/isolation & purification
- Gene Rearrangement
- Genomic Library
- Humans
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Variable Region/genetics
- Lymphoma, Follicular/genetics
- Lymphoma, Follicular/immunology
- Lymphoma, Follicular/pathology
- Molecular Sequence Data
- Mutation
- Oligodeoxyribonucleotides
- Polymerase Chain Reaction/methods
- Proto-Oncogene Mas
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins c-bcl-2
- Restriction Mapping
- Translocation, Genetic
- Tumor Cells, Cultured
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Chen TT. Radial keratotomy: eleven-year experiences. YAN KE XUE BAO = EYE SCIENCE 1992; 8:99-103. [PMID: 1303874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
During the period from 1980 to 1991, Radial Keratotomy (RK) had been done by the author under topical anesthesia in more than 10,000 cases, mostly on both eyes at the same time. Those patients had myopia with a preoperative refractive error between 1.5 and 20.0 diopters (D). The surgical technique consisted of 4, 8, 16 incisions using a diamond knife with micrometer and the diameter of the central clear zone was mostly 3.0 mm and determined by preoperative refractive error. Many different procedures were tried to improve the effect of RK, including redeepening intentional microperforations at 1.5 mm, 3 mm, 5 mm distance from the corneal center. But these procedures had no significant effect 6 months after the operation. Complications such as infection, glaucoma, cataract, etc. were almost none. Results of RK on long term follow up showed hyperoptic tendency, and the visual fluctuation were none or minimal.
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Dunham RA, Ramboux AC, Duncan PL, Hayat M, Chen TT, Lin CM, Kight K, Gonzalez-Villasenor I, Powers DA. Transfer, expression, and inheritance of salmonid growth hormone genes in channel catfish, Ictalurus punctatus, and effects on performance traits. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1992; 1:380-9. [PMID: 1308826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We examined expression and inheritance of salmonid growth hormone genes RSVLTR-rtGH1 cDNA and RSVLTR-csGH cDNA, transferred to channel catfish (Ictalurus punctatus) by microinjection. One to 9 copies of the foreign DNA were inserted in either head-to-tail tandem array at single insertion sites or single copies at multiple insertion sites. All P1 transgenic catfish evaluated produced salmonid growth hormone regardless of the construct. Five P1 x P1 matings were accomplished. The spawning rate and fertility of these P1 transgenics in artificial spawning conditions were comparable to those of normal channel catfish. In two of three years, 100% spawning and 100% hatch were obtained. Percent transgenic progeny observed in the five matings were 20, 52, 7, 47, and 0%, which was lower (P < 0.001, chi 2) than the 75% inheritance expected assuming the P1 brood stock had at least one copy of the foreign gene integrated and were not mosaics in the germ line. At least 7 of 10 P1 were mosaics, and a minimum of 2 of 10 P1 did not possess the salmonid growth hormone genes in their germ line. P1 transgenics grew at the same rate as their nontransgenic full siblings, which is not surprising because the P1 were mosaics. F1 transgenic progeny in two families possessing RSVLTR-csGH cDNA grew 26% faster, to 40 to 50 gm, than their nontransgenic full siblings when evaluated communally. One F1 progeny group produced by RSVLTR-rtGH1 cDNA x RSVLTR-csGH cDNA mating and one F1 progeny group (parents either RSVLTR-rtGH1 cDNA or RSVLTR-csGH cDNA) grew at the same rate as normal full siblings when grown communally to 25 gm and 60 mg, respectively. In families where F1 progeny grew faster than controls, the range in body weight and coefficient of variation for the transgenic full siblings were less than those for controls. In families where F1 progeny grew at the same rate as controls, range in body weight and coefficient of variation were similar for transgenic and normal individuals. The percent deformities observed in P1 transgenics (13.6%) was higher (P < 0.05) than in microinjected P1 nontransgenics (5.1%). Percent deformities in transgenics and control F1 channel catfish was not different (p > 0.05; 0.5 and 2.8%, respectively).
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Chen TT, Lane TA, Doody MC, Caudle MR. The effect of peritoneal macrophage-derived factor(s) on ovarian progesterone secretion and LH receptors: the role of calcium. Am J Reprod Immunol 1992; 28:43-50. [PMID: 1418416 DOI: 10.1111/j.1600-0897.1992.tb00755.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Macrophages and their secretory products, cytokines, play an integral role in many reproductive processes. In this study we examined the effect of conditioned media from cultured human peritoneal macrophages on progesterone production by granulosa cells and the role of calcium in this process. Macrophages were pretreated with various concentrations of a calcium channel blocker (verapamil) or a calcium ionophore (A23187). Macrophage-conditioned media (MCM) or cell-free media that contained calcium channel modifiers were added at three dose levels to cultured porcine granulosa cells. Progesterone production and LH receptor content were determined. Macrophage-conditioned media alone elevated basal progesterone production, but significantly attenuated granulosa cell LH receptor content. These effects were neither potentiated nor suppressed by pretreating macrophages with verapamil. However, production of the LH receptor lowering factor(s) appeared to be suppressed by calcium ionophore. We conclude that (1) one or more factors produced by macrophages have a net stimulatory effect on basal progesterone production and these factor(s) may not be calcium-dependent and (2) macrophage-derived secretory products reduce granulosa cell LH receptor content. The production of these factor(s) may be calcium-dependent.
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Chen TT, Turner DF. Temporomandibular joint innervation in rats: a horseradish peroxidase study. J Formos Med Assoc 1992; 91:808-12. [PMID: 1282407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In the present study, we have used the horseradish peroxidase (HRP) retrograde transport technique to map the trigeminal primary afferent and motor neurons that innervate the temporomandibular joint (TMJ) and the lateral pterygoid muscle (LPM). One to 3.0 microL of 4% wheatgerm agglutinin conjugated horseradish peroxidase (HRP-WGA) solution was introduced unilaterally into the joint cavity of twelve Sprague-Dawley rats. Injections were made from the above, following trephining of the zygomatic arch with a dental bur. Seventy-two hours after surgery, the animals were sacrificed via perfusion-fixation through the left ventricle. The TMJ, both trigeminal ganglia and brain stem were removed, sectioned serially at 50 microns, and reacted according to the tetramethyl benzidine (TMB) technique of Mesulam. Tissues were then examined at the light microscopic level. The injection site showed that the HRP-WGA filled the upper chamber of the TMJ cavity and extended anteriorly to include the LPM. HRP injected into the joint cavity was transported retrogradely to the ipsilateral trigeminal ganglion, where numerous HRP labeled neurons were found. The greatest number of cells were localized in the dorsolateral posterior portion of the ganglion. In the brain stem, numerous labeled cells representing the motor innervation of the LPM were found in a crescent-shaped array on the ventral side of the trigeminal motor nucleus. No labeled cells were found in the mesencephalic nucleus. The results show substantial trigeminal sensory innervation of the TMJ and LPM with no central projection to the mesencephalic nucleus.
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Powers DA, Hereford L, Cole T, Chen TT, Lin CM, Kight K, Creech K, Dunham R. Electroporation: a method for transferring genes into the gametes of zebrafish (Brachydanio rerio), channel catfish (Ictalurus punctatus), and common carp (Cyprinus carpio). MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1992; 1:301-8. [PMID: 1339228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Recombinant plasmids containing the Rous sarcoma virus long-terminal repeat (RSVLTR) promoter linked to either rainbow trout (Oncorhyncus mykiss) growth hormone 1 (rtGH1) or growth hormone 2 (rtGH2) cDNA were linearized and introduced into the fertilized eggs of zebrafish (Brachydanio rerio), channel catfish (Ictalurus punctatus), and common carp (Cyprinus carpio) by both electroporation and microinjection. The latter two species had these rainbow trout constructs (RSVLTR-rtGH1cDNA or RSVLTR-rtGH2) electroporated into both gametes (i.e., sperm and unfertilized eggs) prior to fertilization, into eggs shortly after fertilization, and at the first cell division stage. Survival was determined just after hatching and again between 3 and 5 months after hatching. Polymerase chain reactions and Southern blot analyses were used to detect those individuals carrying the introduced foreign genes 3 to 5 months after hatching, respectively. Individuals analyzed by both methods yielded identical results in a double-blind study. The electroporation results were compared with groups that were microinjected. Although survival was similar, electroporation tended to produce a greater number of transgenic individuals than the microinjection procedure, and many more eggs could be treated per unit time by electroporation than microinjection. Survival was better for common carp when electroporation was performed shortly after fertilization, whereas channel catfish fared better at the first cell division stage. Electroporation prior to and shortly after fertilization, and at the first cell stage appeared to generate a large fraction of transgenic fish. We cautiously conclude that electroporation is an efficient method for introducing foreign DNA into fish gametes and embryos and may be an ideal method for treating large numbers of gametes in a modest period.
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Lu JK, Chen TT, Chrisman CL, Andrisani OM, Dixon JE. Integration, expression and germ-line transmission of foreign growth hormone genes in medaka (Oryzias latipes). MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1992; 1:366-75. [PMID: 1285009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Gene constructs consisting of human growth hormone (hGH) gene driven by promoter/regulatory sequence of mouse metallothionein (mMT), viral thymidine kinase (vTK), rat cholecystokinin (rCCK), or chicken beta-actin (cBA) gene were injected into the cytoplasm of fertilized medaka eggs via the micropyle. More than 49% of the injected embryos survived at hatching. Up to 26% of the survivors showed integration of the introduced gene construct, as determined by polymerase chain reaction analysis and subsequent confirmation by Southern blot hybridization of the genomic DNA. A significant fraction of F1 progeny, derived from crosses between transgenic founders and the nontransgenic individuals, inherited the transgene. Expression of hGH gene was also observed in some of the P1 founders and F1 transgenic progeny carrying mMT-hCG or cBA-hGH gene. Furthermore, the growth performance of the P1 mMT-hGH and cBA-hGH transgenic founders and F1 cBA-hGH F1 transgenic progeny was significantly greater than their full sibling, nontransgenic individuals. In addition to the microinjection experiment, a gene construct containing the long-terminal repeat (LTR) sequence of avian Rous sarcoma virus (RSV) and rainbow trout (rt) GH2 cDNA was introduced into embryos of medaka by electroporation using an exponential decay electroporator. Approximately 70% of the electroporated embryos survived at hatching, and 20% of the survived individuals integrated RSVLTR-rtGH2 cDNA into their genomes. These two techniques will greatly enhance the ability to study regulation of gene expression in transgenic animals during differentiation and development.
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Zhu Z, He L, Chen TT. Primary-structural and evolutionary analyses of the growth-hormone gene from grass carp (Ctenopharyngodon idellus). EUROPEAN JOURNAL OF BIOCHEMISTRY 1992; 207:643-8. [PMID: 1633815 DOI: 10.1111/j.1432-1033.1992.tb17091.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The growth-hormone (GH) gene of grass carp, one of the fastest-growing species of farmed fish, was isolated and the DNA sequenced. Only one GH gene is found in this species. This gene, which is 2.5 kb in length, has five exons and four introns, in common with all of the mammalian and the recently published common-carp GH genes. In the course of vertebrate evolution, the total lengths of the intron and the non-coding region of exon 5 of the GH gene have been shortened by 40-70%, whereas the encoding exons of the gene have been slightly increased. The more closely related species exhibit the closest sequence similarity in their GH genes. For example, the similarity of the exons is 84.1-93.2% between grass carp and common carp (within the same family of Syprinedae), 43.5-82.1% between grass carp and rainbow trout (in different orders of Teleostei) and 45.8-58.6% between grass carp and rat (in different grades of Vertebrata). In addition, similar DNA domains, such as thyroid-hormone-receptor-complex-binding site and cell-type-specific cis elements involved in regulation of expression of rat and human GH genes, have been localized in the corresponding regions of the grass-carp GH gene.
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Watanabe K, Igarashi A, Noso T, Chen TT, Durham RA, Kawauchi H. Chemical identification of catfish growth hormone and prolactin. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1992; 1:239-49. [PMID: 1308206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Isolation and primary structure of growth hormone (GH) and prolactin (PRL) from the pituitary gland of catfish (Ictalurus punctatus) are described. Alkaline extract of the pituitary glands was fractionated by gel filtration on Sephadex G-75, ion-exchange chromatography on DEAE-cellulose, and reversed-phase high-performance liquid chromatography on Octadecyl silica ODS. Catfish GH and PRL were identified by Western blotting with antisera against chum salmon GH and PRL. The catfish GH consists of 178 residues and is the most similar to carp GH, with sequence identity of 77%, although there is an uninterrupted deletion of 10 amino acid residues that corresponds to carp GH (90-99). The PRL is composed of 187 residues, which also exhibits the highest identity (79%) with carp PRL. Sequence identity between catfish GH and PRL is only 27%.
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Indrapichate K, Meehan D, Lane TA, Chu SY, Rao CV, Johnson D, Chen TT, Wimalasena J. Biological actions of monoclonal luteinizing hormone/human chorionic gonadotropin receptor antibodies. Biol Reprod 1992; 46:265-78. [PMID: 1536902 DOI: 10.1095/biolreprod46.2.265] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Several recent studies have elucidated the structure of the mammalian LH/hCG receptor; as reported in the present work, we have developed a series of monoclonal antibodies (mAbs) against the rat ovarian LH/hCG receptor using highly purified receptor as immunogen and by screening hybridomas with purified LH/hCG receptors. The mAbs were able to specifically immunoprecipitate LH/hCG receptors from solubilized preparations of rat ovarian membranes as well as from partially purified preparations. Western blotting with mAb P1B4 detected a probable receptor dimer and a receptor fragment in rat and porcine ovarian tissue but not in other tissues. This mAb also partially inhibited hCG binding to rat and porcine ovarian tissues. The receptor mAbs were able to inhibit hCG-induced progesterone synthesis in cultured human and porcine granulosa cells without affecting cAMP- and FSH-induced progesterone synthesis. The mAb P1B4 was used to demonstrate that the majority of ovarian receptors are internalized after hCG treatment and that in pseudopregnant rats receptors are present in the rough endoplasmic reticulum and in microvesicles. Bovine corpus luteal cells also contained P1B4 binding sites, as detected by immunohistochemical technique. Taken together, these results suggest that the mAbs are specific for the LH/hCG receptor, mAb P1B4 recognizes an epitope that is highly conserved among mammals, and this epitope is probably in the extracellular domain.
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Paynter KT, Chen TT. Biological Activity of Biosynthetic Rainbow Trout Growth Hormone in the Eastern Oyster, Crassostrea virginica. THE BIOLOGICAL BULLETIN 1991; 181:459-462. [PMID: 29304669 DOI: 10.2307/1542366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Juvenile oysters were exposed to seawater containing 10-9, 10-8, and 10-7 M biosynthetic rainbow trout growth hormone (rtGH); the treatment was applied for one five-hour period per week for five weeks. At the end of the five weeks, the animals treated with the two highest concentrations of hormone were significantly longer and had dry tissue weights 50% greater than did the lowest treatment group or the control group. Continuing in vitro experiments on isolated oyster tissue showed that the hormone treatment significantly increased oxygen consumption. Boiled hormone had no effect. In both sets of experiments (whole animals and isolated tissues), the % dry wt (dry wt/wet wt) was significantly higher in all animals and tissues that responded to rtGH. The results demonstrate that rtGH has biological activity in oyster tissues, and this activity may be directly associated with growth regulation in the whole animal. The results further show that bivalve growth is not directly limited by environmental parameters.
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138
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Vestling M, Murphy C, Fenselau C, Chen TT. Disulfide bonds in native and recombinant fish growth hormones. MOLECULAR MARINE BIOLOGY AND BIOTECHNOLOGY 1991; 1:73-7. [PMID: 1845473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Disulfide linkages were characterized for the first time in a fish growth hormone. Trypsin digestion of chum salmon growth hormone, followed by mass spectrometry established that Cys-49 is linked to Cys-161, while Cys-178 is linked to Cys-186. This is analogous to the big loop, little loop pattern found in human growth hormone. Ninety-three percent of the primary structure of a recombinant rainbow trout growth hormone whose cDNA codes for the same amino acid sequence as chum salmon growth hormone was confirmed by mass spectrometric peptide mapping.
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Unger ME, Chen TT, Murphy CM, Vestling MM, Fenselau C, Roesijadi G. Primary structure of molluscan metallothioneins deduced from PCR-amplified cDNA and mass spectrometry of purified proteins. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1074:371-7. [PMID: 1888750 DOI: 10.1016/0304-4165(91)90087-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The primary structure of metallothioneins (MT) of a mollusc, the oyster Crassostrea virginica, was determined by molecular cloning and mass spectrometry of purified proteins. The cloning strategy included PCR amplification of the responsible cDNAs from total cDNA using completely degenerate oligonucleotides (derived from the N-terminal amino acid sequence) and oligo(dT)20 as primers. Primer extension off mRNA was used as an independent determination of the nucleotide sequence represented by the degenerate PCR primers. The deduced amino acid sequence was consistent with characteristics of class I MT. Twenty-one cysteine residues, were arranged in nine Cys-X-Cys motifs, five as Cys-Lys-Cys. A single Cys-X-X-Cys motif was also observed. Two MTs that differ only in the presence or absence of an N-acetyl group exist in this organism. Masses of tryptic peptides of purified MTs corresponded with those of peptides predicted from tryptic cleavages of the deduced amino acid sequence. Allowing for known N-terminal modifications, 96% of the deduced sequence was confirmed by mass spectrometry. Comparison (FASTA algorithm) of the primary structure of the oyster MTs with those of other species indicated a higher similarity with vertebrate MTs than with those of other invertebrates.
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Funkenstein B, Chen TT, Powers DA, Cavari B. Cloning and sequencing of the gilthead seabream (Sparus aurata) growth hormone-encoding cDNA. Gene 1991; 103:243-7. [PMID: 1889749 DOI: 10.1016/0378-1119(91)90280-o] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The cDNA clones encoding gilthead seabream (gsb) (Sparus aurata) growth hormone (GH) have been isolated from a cDNA library prepared from seabream pituitary gland poly(A)+ RNA. The cDNA library was screened using red seabream and rainbow trout GH cDNAs. The complete nucleotide (nt) sequence of gsbGH has been determined. The cDNA sequence codes for a polypeptide of 204 amino acids (aa), including a putative signal peptide of 17 aa. The 5'- and 3'-untranslated regions of the message are 55 and 236 nt long, respectively. The predicted aa sequence of gsbGH revealed 97% homology with red seabream GH, 95% with tuna GH, 85% with yellowtail GH, and 65% with rainbow trout GH.
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Lane TA, Chen TT. Heterologous down-modulation of luteinizing hormone receptors by prolactin: a flow cytometry study. Endocrinology 1991; 128:1833-40. [PMID: 1900778 DOI: 10.1210/endo-128-4-1833] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Although the binding, internalization, and regulation of LH, PRL, and their respective receptors have been extensively studied, it is not known whether the receptors are coordinately regulated. Using double labeling experiments, we have previously shown that receptor-bound LH and PRL can be colocalized in identical endosomes of granulosa cells. We hypothesize that high levels of PRL may induce a heterologous down-modulation of LH receptors, consequently reducing ovarian responsiveness to further gonadotropin stimulation. In this study we used a novel procedure to enrich endosomes containing internalized PRL and to determine whether unoccupied LH receptors were cointernalized in granulosa cells. Porcine granulosa cells were obtained from medium-sized (3-5 mm) follicles and cultured for 4 days in the presence of FSH. Fluorescein isothiocyanate-labeled PRL (FITC-PRL) was used as a ligand to induce internalization of PRL receptors and as a marker to label endosomes. Granulosa cells were incubated with FITC-PRL at either 4 or 37 C for various times. At the end of the incubation, cells were trypsinized to remove surface receptors and then homogenized. The postnuclear fraction containing endosomes and other subcellular organelles was sorted using a FACStar Plus cell sorter. Results from 14 separate sorting experiments showed that 1) FITC-PRL-treated cells exhibited a sorting pattern distinct from that of FITC-BSA-treated or untreated cells; 2) excess unlabeled PRL partially shifted the sorting profile to one similar to that in controls; 3) the differences in sorting profiles were not due to free FITC; and 4) using this method, it was possible to isolate FITC-PRL-containing endosomes that were virtually devoid of other contaminating subcellular particles. Fluorescently positive (FITC-PRL-containing) organelles were collected and assayed for LH receptors using [125I]hCG as a tracer. When the cells were incubated with FITC-PRL at 37 C for 3 h, the number of available LH receptors (as determined by [125I]hCG binding) was 37% higher in particles containing FITC-PRL than in those devoid of FITC-PRL. If the cells were allowed to preincubate with FITC-PRL at 4 C for 10-16 h before raising the temperature to 37 C, the number of available LH receptors in FITC-PRL-containing endosomes was about 7-fold higher than that in FITC-negative endosomes. Results from this study suggest that PRL not only induces internalization of its own receptor, but also causes down-modulation of unoccupied LH receptors.(ABSTRACT TRUNCATED AT 400 WORDS)
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Zelenetz AD, Chen TT, Levy R. Histologic transformation of follicular lymphoma to diffuse lymphoma represents tumor progression by a single malignant B cell. J Exp Med 1991; 173:197-207. [PMID: 1898660 PMCID: PMC2118744 DOI: 10.1084/jem.173.1.197] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
To investigate the clonal relationship between follicular lymphoma (FL) and transformed diffuse lymphoma (tDL), we examined the expression of tumor idiotype, immunoglobulin (Ig) gene rearrangements and sequence of Ig variable genes in paired tissue specimens. All 16 cases analyzed expressed surface immunoglobulin (sIg) on both the FL and the tDL, though the immunophenotype of one case of FL could not be definitively determined. In 14 of 15 cases, the surface immunophenotype was preserved; the exception was likely secondary to a class switch from IgM to IgG. In 12 of 13 cases, antiidiotypic monoclonal antibodies prepared against the FL reacted with the paired tDL. Analysis of Ig gene rearrangements in four cases by Southern blot hybridization showed evidence of clonal relationships in all cases though concordance was not seen with all probes tested (C kappa, C lambda, JH, PFL1, and PFL2). In the one case that had a discordant L chain rearrangement, sequence analysis of the L chain demonstrated a common mature B cell origin for both the FL and tDL. To determine whether tDL arose from one or more FL cells, the sequences of the H chain variable genes were analyzed. Individual clones of the V region gene of the FL showed a random distribution of changes throughout the sequence. In contrast, individual clones of the V region gene from tDL shared numerous nonrandom sequence alterations, implying a common single cell origin. In conclusion, tDL is a mature B cell and arises by transformation of a single FL cell.
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MESH Headings
- Antibodies, Anti-Idiotypic
- Antibodies, Monoclonal
- Base Sequence
- Blotting, Southern
- Cell Transformation, Neoplastic/immunology
- Clone Cells
- Humans
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin Light Chains/genetics
- Immunoglobulin Variable Region/genetics
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/immunology
- Lymphoma, B-Cell/pathology
- Lymphoma, Follicular/genetics
- Lymphoma, Follicular/immunology
- Lymphoma, Follicular/pathology
- Lymphoma, Non-Hodgkin/etiology
- Lymphoma, Non-Hodgkin/genetics
- Lymphoma, Non-Hodgkin/immunology
- Molecular Sequence Data
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Chen TT, Winder AE. APACT: Its Organization and Impact on Resistance to U.S. Tobacco Imperialism. INTERNATIONAL QUARTERLY OF COMMUNITY HEALTH EDUCATION 1991; 12:59-67. [PMID: 20840959 DOI: 10.2190/9f8x-1ncv-d88v-efgx] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This article presents a case study of the formation and first year activities of the Asia Pacific Association for the Control of Tobacco Products (APACT). The case study is organized around five key concepts that address the organizing activity that led this coalition of antismoking groups to create a multinational association in the Asia Pacific region. These concepts are need, team building, funding, management and program development. APACT was born out of the need for Asia Pacific anti-smoking groups to resist US trade sanctions. Sanctions which the US threatened to apply to a number of Asia Pacific nations if those nations refused to eliminate trade barriers to US tobacco marketing and sales. The development of APACT's social action program and its impact is presented for the year 1989-90. Also included is a brief statement of APACT's five-year plan for controlling tobacco related diseases.
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Chang CJ, Chen TT, Lei HY, Chen DS, Lee SC. Molecular cloning of a transcription factor, AGP/EBP, that belongs to members of the C/EBP family. Mol Cell Biol 1990; 10:6642-53. [PMID: 1701020 PMCID: PMC362942 DOI: 10.1128/mcb.10.12.6642-6653.1990] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A C/EBP-like transcription factor, AGP/EBP, that binds to three distinct motifs in the 5'-flanking region of alpha 1-acid glycoprotein gene (AGP) has been identified. Here we report the cloning and properties of cDNA corresponding to mouse AGP/EBP. AGP/EBP and C/EBP share 87% amino acid sequence homology in the "leucine zipper" and its associated DNA-binding domains, while their sequences outside these domains and the sizes of their mRNAs are different. Unlike the limited expression of C/EBP in tissues and cells, AGP/EBP appears to be ubiquitously expressed in tissues like lung, spleen, kidney, heart, testis, and liver and cell lines like p388D1, 129P (hepatoma cell line of C3H/HeJ), FO (mouse myeloma), and L929. Antibody against cloned and expressed AGP/EBP which was raised in rabbits could recognize AGP/EBP from nuclear extract of a number of cells and tissues. On the basis of our findings about the structural relationship and the similarity of motif recognition, we propose that a family of C/EBP-like transcription factors exists.
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Hughes FM, Lane TA, Chen TT, Gorospe WC. Effects of cytokines on porcine granulosa cell steroidogenesis in vitro. Biol Reprod 1990; 43:812-7. [PMID: 2127227 DOI: 10.1095/biolreprod43.5.812] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Recent evidence indicates that factors produced by immune cells (cytokines) may play a role in ovarian function. To explore this possibility, we examined the effects of conditioned medium obtained from cultures of either unstimulated splenocytes (splenocyte-conditioned medium; SCM) or concanavalin A-stimulated splenocytes (CAS) on estrogen and progesterone production by porcine granulosa cells. Granulosa cells were obtained from small (less than 3 mm) or large (greater than 7 mm) follicles and treated with increasing doses of SCM or CAS in the presence or absence of pFSH (100 ng/ml) for 24 h at 37 degrees C. In granulosa cells obtained from small follicles it was found that both SCM and CAS evoked a dose-dependent increase in estrogen but not progesterone production. Estrogen production was no further enhanced by the presence of FSH. Additionally, SCM was able to augment FSH-stimulated progesterone production by these cells, whereas CAS had no effect. Identical treatment of granulosa cells obtained from large follicles demonstrated that both SCM and CAS caused dose-dependent increases in estrogen as well as progesterone production. In response to CAS, FSH augmented progesterone production but exerted a biphasic on estrogen production (inhibiting at lower doses while stimulating at higher doses). In contrast, SCM had no effect on FSH-stimulated estrogen production. Additional controls indicated that the above results could not be attributed to either concanavalin A or serum. Taken together, these findings suggest that cytokines can exert significant effects over granulosa cell steroidogenesis and further imply that these factors may play an important role in the differentiation and developmental regulation of granulosa cell function.
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Abstract
The tobacco industry has lobbied successfully to obtain the support of the United States government for opening Asian Markets to American tobacco products. This paper comments on two issues arising from these efforts: the development of an atmosphere of invasion and resistance to invasion in Asia; and the change in the image of the United States in Asian nations from that of a leader in health to that of an exporter of death. The threat of sanctions and the effects of the open market and United States tobacco company advertising in Japan, Taiwan, and South Korea are noted. Parallels are drawn between the opium wars a century and a half ago in China and the current threat of trade sanctions. Reacting to American policy, an Asia-Pacific Association for Control of Tobacco has been formed and linked with the US Coalition Against Smoking.
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Zhang PJ, Hayat M, Joyce C, Gonzalez-Villaseñor LI, Lin CM, Dunham RA, Chen TT, Powers DA. Gene transfer, expression and inheritance of pRSV-rainbow trout-GH cDNA in the common carp, Cyprinus carpio (Linnaeus). Mol Reprod Dev 1990; 25:3-13. [PMID: 2393581 DOI: 10.1002/mrd.1080250103] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A recombinant plasmid containing the Rous sarcoma virus-long terminal repeat (RSV-LTR) promoter linked to rainbow trout (Salmo gairdneri) growth hormone (GH) cDNA was microinjected into fertilized carp eggs. Genomic DNA extracted from pectoral fin of individual presumptive transgenic fish was analyzed by dot blot and Southern blot hybridization, using the RSV-LTR and/or the GH cDNA sequences as probes. Out of 365 presumptive transgenic fish analyzed, 20 individuals were found to contain pRSV-rtGH-cDNA sequence in the genomic DNA. Expression of the trout GH polypeptide was detected by immunobinding assay in the red blood cells of nine transgenic fish tested. The level of expression, however, varied among the transgenics and could not be correlated with exogenous DNA copy number. Although there was considerable variation in the sizes of the transgenic fish, those microinjected during the one-cell stage were (P less than 0.05) 22% larger, on the average, than their sibling controls. A randomly selected fraction of the progeny derived from crosses between transgenic males and non-transgenic females inherited the foreign DNA. These transgenic progeny grew faster (P less than 0.05) than their non-transgenic siblings.
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Abstract
A range of transgenic animal species have been generated using DNA microinjection, and application of this technique to fish is now showing some degree of success. Studies to optimize microinjection techniques specifically for use with fish, and to investigate possible alternative methods for mass culture, should lead to the commercial production of transgenic fish able to transmit desirable characteristics, such as enhanced growth or disease resistance, to their progeny.
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Porter TE, Chen TT, Frawley LS. Pituitaries transplanted under the renal capsule contain functional growth hormone (GH) secretors and suppress GH and prolactin release from individual eutopic pituitary cells. Endocrinology 1989; 125:3059-67. [PMID: 2510989 DOI: 10.1210/endo-125-6-3059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The extent to which pituitary explants secrete GH requires clarification. In the present study GH release from ectopic pituitary tissue was assessed using the reverse hemolytic plaque assay. In addition, the effects of this tissue on eutopic GH and PRL release were simultaneously investigated. Anterior pituitary glands from adult female donor rats were grafted beneath the kidney capsule of adult male hosts. Four weeks later, this ectopic pituitary tissue and the eutopic pituitary glands of the host animals were removed, dispersed with trypsin, and subsequently assayed for GH and PRL release. Contrary to expectations, we found that 37% of the ectopic pituitary cells were GH secretors. Furthermore, these GH cells remained highly responsive to GRF (10(-7) M), which evoked a 7-fold increase (P less than 0.05) in mean GH plaque area. By comparison, only 28% of these ectopic cells secreted PRL, and this release was not consistently augmented by exposure to TRH (10(-7) M). In the second half of this study we found that the presence of ectopic pituitary tissue severely compromised the secretory capacity of the eutopic pituitary cells. More specifically, GH-releasing factor induced a 3-fold increase in GH secretion from the eutopic pituitary cells of sham-operated control animals, but it enhanced the release from cells of host animals by only 2-fold. Moreover, the response to TRH by the eutopic PRL cells from explant-bearing animals was curtailed to such an extent that it was not significantly greater (P greater than 0.05) than basal release in that group. We conclude that the potential of pituitary explant cells to release GH is far greater than previously believed and that this ectopic hormone production may inhibit hormone release from the eutopic pituitary cells.
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Chen TT, Kineman RD, Betts JG, Hill JB, Frawley LS. Relative importance of newly synthesized and stored hormone to basal secretion by growth hormone and prolactin cells. Endocrinology 1989; 125:1904-9. [PMID: 2507285 DOI: 10.1210/endo-125-4-1904] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
It is generally accepted that under basal conditions there is preferential release of newly synthesized hormone by a number of endocrine cell type, including those that secrete GH or PRL. However, the cellular basis for this phenomenon along with the relative contribution of stored hormone to basal secretion has yet to be clearly established. In the present study, we employed reverse hemolytic plaque assays to monitor basal and stimulated release of GH and PRL from individual cells in which de novo protein synthesis had been blocked. Monodispersed pituitaries from adult male rats were cultured for 21 h in the absence or presence of maximally effective doses of puromycin (100 microM) or cycloheximide (36 microM) and were then subjected to separate plaque assays for GH or PRL. Treatment with puromycin reduced the percentage of GH or PRL secretors (plaque formers) by about half. Coincubation with stimulatory secretagogues did not increase the percentages of GH or PRL secretors in control cultures, but returned the proportion in puromycin-treated cells to normal, demonstrating that cells which failed to secrete basally could still release hormone from their stored pools when stimulated. Very similar results were obtained when these experiments were repeated with cycloheximide. Taken together, these results demonstrate that only a fraction of the cells that release GH or PRL are dependent upon newly synthesized hormone for basal secretion; the remainder appear capable of mobilizing stored hormone for this purpose even in the absence of stimulation.
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